# US 11,111,774 B2 · Sensor transportation apparatus

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- Number: US 11,111,774 B2
- Document ID: US11111774B2
- Status: Granted
- Kind: B2
- Application number: 16/759,847
- Filed: 2018-10-29
- Published: 2020-10-01
- Granted: 2021-09-07
- Earliest claimed: 2017-11-01
- Assignees: Petromac IP Limited
- Applicants: Petromac IP Limited
- Inventors: Stephen Peter McCormick
- Web page: https://patentgrep.com/patent/US11111774B2

## CPC

- E21B 17/1057: {Centralising devices with rollers or with a relatively rotating sleeve (E21B17/1014 takes precedence)}
- E21B 47/013: Devices specially adapted for supporting measuring instruments on drill bits
- E21B 23/14: for displacing a cable or a cable-operated tool, e.g. for logging or perforating operations in deviated wells
- E21B 47/01: Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like
- E21B 47/017: Protecting measuring instruments
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS

## Abstract

A sensor transportation apparatus for conveying a sensor assembly through a wellbore comprises at least one engagement structure to connect the sensor transportation apparatus to the sensor assembly, at least one axle, a bearing connected to the axle, and a wheel connected to the bearing and provided with a shaft seal to prevent or reduce debris from the wellbore entering the bearing, and a lubrication delivery system to provide a lubricant to the bearing at a pressure which is greater than ambient wellbore pressure. The lubrication system comprises a bellows formation, and the apparatus comprises a housing to contain the lubricant, the housing in fluid communication with the bearing, the bellows formation sealingly mounted to the housing with at least a portion of the bellows received within the housing.

## Claims

### Claim 1

A sensor transportation apparatus for conveying a sensor assembly through a wellbore, the sensor transportation apparatus comprising:
at least one engagement structure to connect the sensor transportation apparatus to the sensor assembly,
at least one axle, at least one wheel, a bearing connected to the axle between the wheel and the engagement structure, a shaft seal to prevent or reduce debris from the wellbore entering the bearing, and
a lubrication delivery system to provide a lubricant to the bearing at a pressure which is greater than an ambient wellbore pressure, wherein the lubrication system comprises:
a spring bellows formation, and the apparatus comprising a housing to contain the lubricant, the housing in fluid communication with the bearing, the spring bellows formation sealingly mounted to the housing with at least a portion of the spring bellows formation received within the housing to provide a bias force so that the pressure in the lubricant is greater than the ambient wellbore pressure of a wellbore fluid surrounding the device;
a flexible member, an outer surface of the flexible member in communication with wellbore fluids surrounding the apparatus in use; and
a liquid contained in a sealed chamber defined, at least in part, by the interior of the spring bellows formation and an inner surface of the flexible member.

### Claim 2 (depends on 1)

The apparatus as claimed in claim 1, an exterior of the spring bellows formation is exposed to or facing the lubricant in use.

### Claim 3 (depends on 1)

The apparatus as claimed in claim 1, wherein the flexible member is a resilient diaphragm.

### Claim 4 (depends on 1)

The apparatus as claimed in claim 1, wherein the chamber has an invariable volume, such that deflection of the spring bellows formation causes deflection of the flexible member and vice-versa.

### Claim 5 (depends on 1)

The apparatus as claimed in claim 1, wherein the liquid comprises silicone oil.

### Claim 6 (depends on 1)

The apparatus as claimed in claim 1, wherein the lubricant is provided in a volume defined in part by the housing and an exterior of the spring bellows formation and the shaft seal.

### Claim 7 (depends on 6)

The apparatus as claimed in claim 6, wherein the bearing is contained in said volume, immersed in the lubricant.

### Claim 8 (depends on 6)

The apparatus as claimed in claim 6, wherein prior to use, the lubricant is forced into the volume, compressing the spring bellows formation.

### Claim 9 (depends on 1)

The apparatus as claimed in claim 1, wherein the spring bellows formation maintains a higher pressure in the lubricant than the liquid filling the interior of the spring bellows formation and hence the wellbore fluid.

### Claim 10 (depends on 1)

The apparatus as claimed in claim 1, wherein the spring bellows formation comprises a plurality of metal rings.

### Claim 11 (depends on 10)

The apparatus as claimed in claim 10, wherein the metal rings are stainless steel alloy rings.

### Claim 12 (depends on 1)

The apparatus as claimed in claim 1, wherein the bearing is between the wheel and the axle.